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VULNERABILITIES

CVE-2026-57963 Details

Description

An attacker who can send HTML chat messages (via Matrix or XMPP) can inject arbitrary styled content, phishing links, and CSS that manipulates the chat UI. This vulnerability was fixed in Thunderbird 152.0.1 and Thunderbird 140.12.1.

Metrics

CVSS 3.x Severity and Vector Strings:

CNA: CISA-ADPCVSS-B:6.5 MEDIUMVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

References to Advisories, Solutions, and Tools

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URLSource(s)Tag(s)
https://bugzilla.mozilla.org/show_bug.cgi?id=2042910 [email protected]Permissions Required
https://www.mozilla.org/security/advisories/mfsa2026-63/ [email protected]Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-64/ [email protected]Vendor Advisory

Weakness Enumeration

CWE-IDCWE NameSource
CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')CISA-ADP

Affected Products

ProductVersions
mozilla thunderbird
< 140.12.1
< 152.0.1

CPE

  • cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*
  • cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*

Remediation

  • No remediation found in references.

Change History

5 change records found show changes

QUICK INFO

CVE Dictionary Entry:
CVE-2026-57963
NVD Published Date:
Jul 1, 2026
NVD Last Modified:
Jul 6, 2026
Source:
[email protected]
CVE-2026-57963 Details - Not Deferred